Dental matrix.



PATEN'TED OCT. 3, 1905..

F. E. ANDERSEN. DENTAL MATRIX. APPLICATION FILED DEO.Z7. 1904.

Wu? eases: A. 45. W1 M.

FREDRIK E. ANDERSEN, OF RED WING, MINNESOTA.

DENTAL MATRIX.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed December 2'7, 1904. Serial No. 238,289.

To all whom it may concern:

Be it known that I, FREDRIK E. ANDERSEN, a citizen of the United States, residing at Red ing, in the county of Goodhue and State of Minnesota, have invented a new and useful Dental Matrix, of which the following is a specification.

My invention relates to improvements in dental matrices, and particularly to a matrix designed to furnish a temporary back wall against which to insert fillings in the anterior teeth. This appliance is specially adapted for inserting gold fillings in proximal cavities which extend through the tooth to the lingual surface or, in other words, proximal cavities in which are included parts of both the labial or anterior surface and the lingual or posterior surface. v

My invention has for its object to assist the operator in filling such cavities. By enabling the dentist to insert his fillings from the labial instead of the lingual side of the tooth time and labor are saved and a more perfect and durable filling is produced, because the operator has direct access to all points in the cavity from the anterior opening,

and the necessity of inserting and malleting the gold from the posterior opening is practicall y eliminated. Thus, for example, in proximal cavities which do not extend to or include a part of the incisal edge of the tooth the matrix insures a perfect condensation of the gold to the margin of the cavity nearest the incisal edge, which has heretofore in many cases been difficult, if not impossible.

My appliance may be said to consist of a combined matrix and separator.

Figure 1 is a front view showing my invention attached to the incisors of the upper jaw ready for the operation of filling a cavity in one of said incisors. Fig. 2 is a side elevation. Fig. 3 is a perspective view showing the device as it would appear from inside of the mouth when in position. Fig. 4 is a sectional view of Fig. 2, taken on the line X X. Fig. 5 is a front view of the detachable matrix, and Fig. 6 is a back view of the same.

In the drawings, A and B represent, respectively, the front and back frames of my appliance; (J, the separator-bands; D, an expander in the form of a turnbuckle for spreading the outer ends of the separator-bands, and E a removable matrix.

A and B consist, substantially, of quadrilateral frames. The sides of the frameAarepivotally connected at their angles, while the corresponding sides of the frame B are rigidly attached to each other. The frames are joined at their lower sides 1 and 2 by means of an adjusting-screw 3 and at their upper angles 4: and 5 by the bands C, which are the separators, hereinafter more particularly described. The frame B carries in the slots 6 a removable matrix E, made of vulcanized rubber or other suitable elastic material, said material being faced both front and back by a sheet of suitable resilient metal or alloy 7. The upper and lower edges of the posterior facing just referred to serve as guides or flanges 8, adapted to slip into the slots 6, which taper from the side of the frame B at which the matrix is inserted toward the opposite side of said frame for the purpose of binding and holding the matrix in position. My appliance is furnished with a set of these matrices having front surfaces of varying forms, suited to fit the different formations and positions of the inner surfaces of the teeth to which the matrix may be adjusted. The upper side of the frame A is formed by the expander D, which, as I prefer to construct it, consists of right and left screws 9, threaded into a casing 10, said casing being provided with perforations 11, adapted to admit a dental tool -or a wrench for the purpose of turning the casing, and thereby extending or contracting the upper side of the frame A.

It is obvious that some other suitable form of expander capable of forcing the bands C apart may be substituted for the turnbuckle arrangement just described without departing from the spirit of this invention. The separators C are bands of resilient material, strong in resisting tension, connected with the upper corners of this frame A, preferably by pivots, and rigidly attached to the frame B at its upper corners. It is apparent, therefore, that the extending of the turnbuckle D tends to spread the separators, while its contraction tends to draw them together.

In operation my invention is applied to the teeth of the patient, as shown in Fig. l the screw 3 being adjusted to conform to the teeth. The front surface 12 of the matrix is thus brought into contact with the inner surface of the teeth and forms a back wall for the filling to be inserted. While the device is being applied the medial portions of the separator-bands C between the frames A and B are close together. When the matrix has been adjusted to the posterior surface of the teeth, the casing 10 on the expander D is turned with the IIO aid of a wrench or convenient dental instrument, and the separator bands 0 are thus forced close about the gingival of the adjoining teeth under the gum, and as this turning continues the teeth are gradually spread apart, and the filling may be inserted and malleted through the opening formed from the labial side of the teeth. The matrix being held lirmly against the lingualsurface of the tooth to be operated upon, forms a posterior wall to the cavity against which the gold may be packed, and thus insures a thorough condensation of the gold or other filling along the lingual portion of the cavity.

1 have shown and described the form of appliance which I deem best adapted to produce the desired results; but it is not my intention to confine myself, nor do I understand that the prior art limits my invention to the specific formation and connection of parts illustrated.

Having described my invention, what I claim as new, and desire to protect by Letters Patent, is-

1. The combination of a dental matrix with a pair of spreader-bands, a turnbuckle positioned between the outer ends of said bands, and means for supporting and adjusting said parts.

2. An appliance of the class described, comprising a matrix carried bya frame, a pair of spreader-bands attached to said frame, a second frame pivoted at its angles and to the outer ends of said bands, and means for adjusting said frames,and separating said bands.

3. A device of the class described, comprising a pair of frames, one of which carries a dental matrix while the other is connected at its upper angles by a turnbuckle, and a pair of separator-bands attached at their inner ends to the first-mentioned frame and at their outer ends connected with the upper angles of said second frame.

at. The combination of a separable dental matrix, provided with a malleting-surface, separator-bands provided with supports for their ends, means for adjustably connecting said supports, and means for spreading said bands apart.

5. In a device of the class described,the combination of a dental matrix, a pair of separator-bands, provided with a turnbuckle and adapted to move in opposite directions when said turnbuckle is extended, suitable frames for supporting said parts, and threaded means for connecting the frames.

6. A device of the class described, comprising a pair of frames provided with athreaded connection, a dental matrix carried by one of said frames, a pair of separator-bands attached to said frames, and means for drawing said bands together and forcing them apart.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FREDRIK E. ANDERSEN.

W'itnesses:

E. M. BonsnL, JOHN M. LYNCH. 

